Professionals taper, with the last high intensity + high volume session about 10 days out, as their risk of injury is great, and if they do get injured, they can recover in time for their major championships. As I just stated, you only need to taper before a major competition near the end of the year, typically. Of course, you should 'taper' before every competition, but only for a few days. Further, essentially you should be 'tapered' before every high intensity session, to ensure the athlete is fully recovered and able to get the most gains out of any single high intensity training session. You may be able to taper up to 14 days out, but I think history has shown us this is a bit out dated, and the best results are usually somewhere between 7-14 days.

Since lower-level athletes (high school for example) may only need 5-7 days to taper before their major competitions, as their risk for injury is less as they can never reach the risky speeds of a world-class sprinter, for example. Thus, an 11.0 high school sprinter's "engine" doesn't get as hot as a sub-10 athlete's. So it takes them less time to 'cool down' anyways. That being said, this doesn't mean that a low level athlete should train more frequently than a high level athlete with access to multiple therapies. A schedule of three high intensity sessions per week may be easy to handle for someone with a PB of 10.3, but someone with a PB of 12 seconds would never be able to handle such a load. The 12 second sprinter can only generate so much stimulation in one single session, and thus has greater limits. The same applies to his recovery. He is not going to be able to recover from a speed session in 48 hours like the 10.3 sprinter can. The 12 second sprinter's battery is smaller, and thus drains faster. For this reason, you need not go more than two high intensity sessions per week with lower level athletes. You still may not go for a 3-HI with the 10.3 sprinter either, as it is highly individual, but chances are he will recover better. Just a clarification is all, simply that, though lower level athletes may have a shorter taper, this doesn't mean they need less recovery than a high level athlete, in fact, they need more.